a. Field of the Invention
The present invention pertains generally to aeration systems used in water bodies and more particularly to solar powered aeration systems that incorporate a power storage battery.
b. Description of the Background
It is well known that forced aeration of aqueous bodies has beneficial effects. Aeration promotes desirable fish, plant, and microbial organisms while reducing algae growth. Further, active gaseous aeration can reduce phosphorous, iron, and nitrogen in eutrophic water bodies as well as water reservoirs and storage tanks.
Sufficient oxygen concentration in water on the order of 5 ppm or higher is essential for efficient aquaculture of fish and other marine animals. Fish do not feed well at low oxygen concentrations and will die from prolonged exposure to oxygen levels as low as 0.5 ppm. It is common for fish farmers to use aeration systems of various sorts to improve the fish habitat and increase production. These devices may be simple paddle wheels that aerate water by splashing and slinging water into the air or by diffusers of various sorts supplied by air pumps at predetermined depths or at the bottom of the water body.
In eutrophic water bodies, such as a pond or lake, the oxygen levels shift dramatically throughout the day. During the day, sunlight promotes circulation of the water that increases the oxygen content. However, at night, the circulation is halted and the oxygen levels decrease. Thus, the period of lowest oxygen levels are typically the hours just before and after daybreak. Artificial aeration systems can be used to enhance oxygen levels at such periods. A limitation of prior art in solar powered systems is that the aeration only occurred during periods of sunshine, which is the period that the aeration is least needed.
Oxygenation by aeration is used in various sewage treatment processes wherein high oxygen level is essential to the growth of beneficial microbes. Further, active aeration forces water circulation essential to efficient sewage treatment. The circulation has added benefits of outgassing unwanted compounds and precipitating other harmful compounds. An excellent discussion of this practice is taught in U.S. Pat. No. 3,956,432 to Hilling which is specifically incorporated herein by reference for all that it discloses and teaches.
Aeration can be used as a method of increasing the health of a pond or lake. Algae growth can be halted by increasing oxygen levels and the aeration process can precipitate iron from the water and offgas H2S, CO2, NH4, as well as other detrimental compounds from the water. The use of a forced aeration system can restore a water body to health by reestablishing the proper nutrients necessary to sustain aquatic life.
One of the practical limitations of conventional aeration systems is the requirement for a power source. For locations away from the electrical power grid, such as a remote lake, the cost of supplying power in the form of either electrical power lines or a remote generator is prohibitive. Further, the power supply results in a high recurring cost.
Oxygen levels in a lake or other eutrophic water body can become stratified, with water at the top having higher oxygen content than the water at the bottom. For the fish farmer desiring to more efficiently produce fish, the stratification of the lake makes a large portion of the lake less productive. Some prior art, such as U.S. Pat. No. 4,906,359 to Cox, Jr., which is specifically incorporated herein by reference for all that it discloses and teaches, only provide aeration to the top layer of a water body and do not promote the oxygenation of the entire lake.
In wintertime, ice may cover a body of water and further compromise the oxygen levels, since no oxygen is being introduced to the body of water. Since the water is not aerated during the period that the ice covers the body of water, low oxygen levels can result in fish kill since the water body is effectively sealed from any further oxygenation. Bottom aeration in the winter months may prevent permanent ice formation.
Aeration systems comprising air pumps generally force air into the body of water and have some mechanism for dispersing the air into the water. An excellent history of prior art in this area is found in U.S. Pat. No. RE 33,899 to Tyer, which is specifically incorporated herein by reference for all that it discloses and teaches. The Hilling patent teaches a device for use in a man made pool for water treatment and discusses a manifold system that lays in the bottom of the pool for aeration.
The use of solar power for aeration has limitations in that the cost of the solar panels tends to be high with respect to the power output. In order to make better use of the high cost of the solar panels, the most efficient aeration system should therefore be employed. It is well known that laminar flow of a water column comprised of fine bubbles is the most efficient method of transferring oxygen into a body of water. Increasing the depth of the water column source further increases the oxygen transfer.
It would therefore be advantageous to provide an aeration system that can operate at predetermined times to coincide with the periods of low oxygen in a water body. Further, a solar powered system could be used in remote locations or where the operator would like to avoid a continual operating cost and also avoid the capital cost of electrical power line installation. Also, it would be advantageous to provide aeration from the bottom of a water body that is able to circulate and destratify the water contained therein. Further, the use of a laminar flow water column of fine bubbles would be advantageous to maximize efficiency. The use of fine bubbles maximizes the oxygen transfer to the water, which is advantageous in solar applications. Matching the compressor size, the depth of the water body, and the diffuser size further enhances the overall efficiency of the system.
The present invention overcomes the disadvantages and limitations of the prior art by providing a solar powered aeration system for water bodies that includes an electrical battery for either continuous operation or operation at periods where the oxygen level is at its lowest, such as at night. Further, the solar powered system can be used without attachment to the power grid and without an energy source that must be replenished, such as propane, gas, or other power source.
The present invention may comprise a controller that can operate the device only at predetermined periods of low oxygen levels. The controller may further comprise an oxygen sensor that provides direct feedback to the controller for keeping the water""s oxygen levels above a certain point.
The present invention may have an optional oxygen generator attachment that increases the oxygen absorption of the water significantly. Further, an ozone generator may be installed in place of or in addition to the oxygen generator, significantly increasing oxygen absorption.
The present invention utilizes a laminar flow column of fine air bubbles to maximize oxygen transfer. Further, the laminar flow column enhances circulation more so than a turbulent flow diffuser because more water is entrained in the rising column of air bubbles. The laminar flow column is formed by matching the diffuser capacity, the air compressor capacity, and the pressure drop of the air line in such a manner that the air bubble and water column from the diffuser is laminar.
The location of the diffuser at the bottom of the body of water, coupled with the efficient circulation of the laminar flow column, effectively destratifies the body of water. Destratified water minimizes areas of the body of water that are less likely to support aquatic life, increasing the capacity of the body of water to support fish and other desirable life forms.
All of the electrical components, including any control devices, are mounted on the shore of the body of water, and the only part of the system in the water is the diffuser and the air line attached thereto. Since the components are located on the shore, they are easy to service and require less protection than if they were mounted on a floating platform or underwater. The solar panel especially benefits from mounting on land, since the mounting apparatus may be firmly fixed to the ground and therefore remains stable during high winds or other weather. Further, land based solar panels may be attached to a sun tracking device for increased power output.
The present invention may therefore comprise a solar powered device for aerating a body of water comprising: one or more solar power source being electrically connected to one or more batteries being electrically connected to one or more air compressors, the power sources, the batteries, and the compressors being mounted outside of the body of water, and one or more diffusers that are pneumatically connected to the compressor, the diffusers being mounted in the body of water.
The present invention may further comprise a solar powered device for aerating a body of water comprising: one or more solar power sources being electrically connected to one or more batteries being electrically connected to one or more air compressors, one or more oxygen generators being electrically connected to the batteries and pneumatically connected to the air compressors, the power sources, the batteries, the compressors, and the oxygen generators being mounted outside of the body of water, and one or more diffusers that are pneumatically connected to the oxygen generators, the diffusers being mounted in the body of water.
The present invention may further comprise a solar powered device for aerating a body of water comprising: one or more solar power sources being electrically connected to one or more batteries being electrically connected to one or more air compressors, one or more ozone generators being electrically connected to the batteries and pneumatically connected to the air compressors, the power sources, the batteries, the compressors, and the ozone generators being mounted outside of the body of water, and one or more diffusers that are pneumatically connected to the ozone generators, the diffusers being mounted in the body of water.
The present invention may further comprise a solar powered device for aerating a body of water comprising: one or more solar power sources being electrically connected to one or more batteries being electrically connected to one or more air compressors, one or more oxygen generators being electrically connected to the batteries and pneumatically connected to the air compressors, and one or more ozone generators being electrically connected to the batteries and pneumatically connected to the oxygen generators, the power sources, the batteries, the air compressors, the oxygen generators, and the ozone generators being mounted outside of the body of water, and one or more diffusers that are pneumatically connected to the ozone generators, the diffusers being mounted in the body of water.
The advantages of the present invention are the efficient aeration of water bodies without connection to the electric power grid or to an energy supply that requires replenishment, such as gas, propane, or other energy sources. Further, the present invention has a compressor and diffuser that are matched to produce laminar flow of a column of fine bubbles and water that maximizes oxygen absorption and water circulation at the highest efficiency possible. The diffuser for the present invention is located at the bottom of the body of water, further maximizing circulation and oxygen transfer. The present invention may be outfitted with an oxygen generator and/or an ozone generator for further increasing the efficiency of the oxygen transfer.